Re: pressure hull design (Fwd)

[John Brownlee <jonnie@chronic.lpl.arizona.edu>]

	Bill,

	Well, strictly speaking I'd need one one other variable, the
diameter of your pipe.  Not that it will probably matter at 5/8" steel,
though. For the sort of dives you are talking about, your margin of safety
is positively huge for a cylinder with any reasonable diameter, as you are
aware. When someone starts talking about spheres to me, I usually connect
that with deep operating depths where it's usually worth the caution.
	My intention was not to imply that common sense is non sequitur,
but that if you -really- want to know what the theoretical crush depth is
often times a formula won't give an accurate result alone. For me, doing
the calculations is one of the only good things to come from a painful
history of nasty math courses, so I like to. Conservative thinking can
certainly be just as good as any wad of equations. 
	
	

							John

John Brownlee
Lunar and Planetary Lab
University of Arizona
jonnie @ lpl . arizona . edu